Ann Croissant, president of the Glendora Community Conservancy and the San Gabriel Mountains Conservancy, gets excited as she discovers that the thread-leafed brodiaea survived after being burned from the recent Colby Fire at Glendora Conservancy land along Colby Trail in Glendora on Jan. 21.
Watchara Phomicinda — Staff Photographer

Act one of a Southern California wildfire features walls of flames, flying embers, dense smoke and charred rubble.

Most residents aren’t aware of the drama’s delayed second act starring fire followers. These can be dormant wildflowers resurrecting as rudimentary stalks, popping up from black ash and turning into show-stopping pallets of purples, fuchsias and yellows. Or they can be opportunistic black-backed woodpeckers, house wrens and flycatchers feasting on a fresh array of insects, or furry-tailed mule deer grazing on new-growth grasses sprung by a suddenly cleared understory.

In short, the natural ecology of the chaparral-covered mountains and the coastal sage scrub habitats enable numerous plant and animal species to survive, even flourish, after a fire. A fire or some other disturbance such as erosion, almost always triggers the plant’s survival mechanism, say scientists.

Unlike animals, plants don’t flee fire. They stay. And they benefit.

Heat from a forest fire cracks open seeds of plants and certain pine trees, leading to germination. Chemicals from charred wood stimulate the reproductive system of many native plants. Phosphorous — the white residue from burned leaves add to the nutrients in the soil. Levels of nitrogen, an essential element for life, increase in the soil of a charred hillside.

“What most people don’t understand is when they look up at the hillside say after the Colby Fire and they say it is a moonscape. That is the way it is supposed to be. It is the natural way of things,” explained Rick Halsey, director of the California Chaparral Institute in San Diego.

The Colby Fire burned nearly 2,000 acres, destroyed five homes and damaged 17 structures in and around Glendora and Azusa and the Angeles National Forest last month. The oaks are singed but not destroyed, the fire followers waiting in the wings.

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The recent conflagration reminded Altadena historian Michele Zack of the 2009 Station Fire, which burned 161,000 acres from La Cañada Flintridge to Sunland in the largest fire in Los Angeles County history. The fire claimed the lives of two firefighters.

Zack, who has written several books on the history of Altadena and Sierra Madre, remembers a walk sponsored by Altadena Heritage just seven months after the fire. Eighteen-inch tall stems attached to lavish purple flowers, known as Phacelia grandiflora, grew up in waves around the blackened manzanita bushes of El Prieto Canyon.

Homeowner Theo Clark, whose house was once owned by Owen Brown, son of John Brown, the abolitionist from Harper’s Ferry was saved by firefighters, led the walk that May day in 2010. He said after 32 years of living in the canyon, he had never before seen the Phacelia bloom.

Phacelia grandiflora is one of several native plants listed by Halsey as “endemic or frequent fire followers.” Others include: whispering bells, popcorn flower, fire poppies, lupine and snapdragon. These appear after a fire, he said.

Other native plants can re-sprout after a fire, or their seeds can be germinated by a fire. Golden eardrops, or their official name, Ehrendorferia chrysantha, need fire to germinate, according to a late 2012 article published in The Wildlife Professional, a research journal.

The article, “A New Forest Fire Paradigm,” said that while forest fires damage property or take life and are viewed as catastrophic by the general public, in actuality they are “both natural and necessary to maintain the integrity of dynamic, disturbance-adapted forest systems.” The authors, like many others in the field, advocate for a new paradigm which says forest fires are “an ecological necessity.”

Up from the ashes

Just five days after the fire had consumed a major portion of the Glendora and Azusa hillsides, Ann Croissant, the founder and board president of the Glendora Community Conservancy did not know what to expect.

In 1991, this area was the first piece of land preserved by the group. With the help of $1.5 million in voter-approved Proposition A dollars, the conservancy bought 50 acres of the oak-studded Colby Canyon and lilting meadows once used as citrus groves now being restored to their natural habitat.

Though that number has grown to 700 acres preserved, 400 or so suffered damage in the Colby Fire.

The conservancy’s first purchase launched a movement that later included other conservancies; among them the state San Gabriel & Lower Los Angeles Rivers and Mountains Conservancy. The purchase directly prevented a 30-home development.

The reason? The discovery of a federally and state-listed endangered plant, the thread-leaved brodiaea, or Brodiaea filifolia. Before that day in 1991, the shy, violet-flowered plant was seen in one other spot in California, the species-rich Santa Rosa Plateau in Riverside County.

If the Colby fire was too hot, it may have wiped out the plants, roots and all. A “cooler” fire could actually stimulate bloom volumes two-to-threefold come May, when the city celebrates Brodiaea Month.

Within minutes, Croissant spotted green shoots of the brodiaea poking through the shiny black ash. This was new growth.

“You can see them over there. Look! Look!,” Croissant was now jumping up and down. “They are all over. They are coming back. There are whole clusters out here.”

Halsey said the brodiaea existed before the fire but is aided by the clearing out of other weeds and branches that blocked the sun’s rays. “Once the fire came through, it threw up its leaves and said wow, what is happening? The physiological response tells the bulb it is time to party,” Halsey said.

Red clay earth protected the brodiaea’s unique roots, Croissant said. Sometimes plants bulbs or corms can lay dormant for years. Halsey said a plant can remain absent for centuries only to be awakened by a fire.

Though no one will know until May, Croissant believes the brodiaea’s purple blooms could be bigger and better than 2012, when the number of plants grew from 900 in three different hillsides in Glendora, to 7,000 plants. “We may have double or triple the blooms this year,” she said.

A post-fire laboratory

Scientists expect to see fire follower plants this spring in the area of the Springs Fire, which burned 24,000 acres in Ventura County and into western Los Angeles County in May. It also destroyed 15 homes. The same could be true of the area burned by the Powerhouse Fire in North Los Angeles County, also in May.

“You will find all those same things out there: Plants that require heat for seeds to crack they may germinate that year. These would include mountain lilac and bush poppy,” Halsey said.

However, scientists point out differences among the coastal sage scrub habitat and that of the chaparral found farther inland. Less is known about fire followers in coastal areas because most of that habitat has been destroyed by development. Some say chaparral habitat is more resilient.

The other factor is moisture.

Climatologists predict little-to-no rain this year, as Southern California enters the third straight year of a drought. But that may not stop fire followers, Halsey pointed out, only delay their debut for a year or two. “They can hang out for a couple of years and not germinate and wait for rain,” he said.

Croissant said the recent rains have gently moistened the burned-out soil, preparing it to take more precipitation. “We are expecting a phenomenal bloom in May,” she predicted.

Edward Bobich, a professor of biology at Cal Poly Pomona, has studied a different kind of fire follower, the Southern California black walnut tree.

Though once dominant in the Hollywood Hills, Santa Monica Mountains and coastal ranges, this tree has nearly left the area due to development. Significant last stands can be found in Chino Hills State Park and near Bonelli Regional Park in San Dimas, where a fire burned a hillside nearly 10 years ago.

A burned out walnut tree can grow a new shoot up to 5 feet in length in a year, he said. “The plant resprouts from the base. It has a woody tuber that produces new stems,” Bobich said.

To plant or not

Fires have generated the debate: Do you replant or not?

Most botanists and fire ecology experts say the answer is no.

“As a biologist, I would say planting trees, whether native or non-native, is a bad idea,” Bobich said. Instead, the best thing to do is to clear away invasive species such as mustard grass to make way for native plant rebirth, something the fire has already started,” he said.

Lili Singer, a horticulturist and director of special projects with the Theodore Payne Foundation in Sun Valley, an organization specializing in nurturing and distribution of native, drought-resistant plants, said the thinking in the last 10 years has moved away from re-planting in a burned out forest or chaparral hillside.

“The Earth has a way of healing itself,” Singer said.

Croissant will do replanting on March 1 but only in a nearby meadow not touched by the fire. There, where citrus groves have denuded the natural landscape, she’s planting a Children’s Forest with oaks, native plants such as clarkias and poppies, that will restore the area to its original form.

While standing on the ash-covered meadow where the brodiaea are sprouting, she said the best thing to do there is nothing.

Halsey agreed. “Everyone wants to plant trees or make the black go away,” Halsey said. “People are impatient. The best thing to do is accept the fact this area burned and nature will recover without our help.”